Switched Capacitor Nine-level inverter with reduced components for Grid connected PV systems using Fuzzy logic controller

The novel use of a three-phase switched capacitor SC nine-level inverter in a PV system is described in this article. It has a low input voltage, fewer components, and is grid-connected. The primary benefit of the suggested inverter is high voltage gain, which is attained by switching capacitors in series and parallel to raise the output voltage with the proper switching management. It is simpler to design a fuzzy logic controller to increase the infusion of solar energy into the electrical network. The MATLAB/Simulink environment's findings demonstrate that the suggested fuzzy logic controller performs well under a range of illumination levels. In comparison to the traditional PI controller, the total harmonic distortion (THD) obtained is less than the limit of 0.67 %. Good spectrum analysis and strong performance with fewer components are made possible by the nine-level SC inverter

A novel modified sine-cosine optimized MPPT algorithm for grid integrated PV system under real operating conditions

This research work presents a modified sine-cosine optimized maximum power point tracking (MPPT) algorithm for grid integration. The developed algorithm provides the maximum power extraction from a photovoltaic (PV) panel and simplified implementation with a benefit of high convergence velocity. Moreover, the performance and ability of the modified sine-cosine optimized (MSCO) algorithm is equated with recent particle swarm optimization and artificial bee colony algorithms for comparative observation. Practical responses is analyzed under steady state, dynamic, and partial shading conditions by using dSPACE real controlling board laboratory scale hardware implementation. The MSCO-based MPPT algorithm always shows fast convergence rate, easy implementation, less computational burden and the accuracy to track the optimal PV power under varying weather conditions. The experimental results provided in this paper clearly show the validation of the proposed algorithm

IMPROVEMENT OF POWER QUALITY OF HYBRID GRID BY NON-LINEAR CONTROLLED DEVICE CONSIDERING TIME DELAYS AND CYBER-ATTACKS

Power Quality is defined as the ability of electrical grid to supply a clean and stable power supply. Steady-state disturbances such as harmonics, faults, voltage sags and swells, etc., deteriorate the power quality of the grid. To ensure constant voltage and frequency to consumers, power quality should be improved and maintained at a desired level. Although several methods are available to improve the power quality in traditional power grids, significant challenges exist in modern power grids, such as non-linearity, time delay and cyber-attacks issues, which need to be considered and solved. This dissertation proposes novel control methods to address the mentioned challenges and thus to improve the power quality of modern hybrid grids.In hybrid grids, the first issue is faults occurring at different points in the system. To overcome this issue, this dissertation proposes non-linear controlled methods like the Fuzzy Logic controlled Thyristor Switched Capacitor (TSC), Adaptive Neuro Fuzzy Inference System (ANFIS) controlled TSC, and Static Non-Linear controlled TSC. The next issue is the time delay introduced in the network due to its complexities and various computations required. This dissertation proposes two new methods such as the Fuzzy Logic Controller and Modified Predictor to minimize adverse effects of time delays on the power quality enhancement. The last and major issue is the cyber-security aspect of the hybrid grid. This research analyzes the effects of cyber-attacks on various components such as the Energy Storage System (ESS), the automatic voltage regulator (AVR) of the synchronous generator, the grid side converter (GSC) of the wind generator, and the voltage source converter (VSC) of Photovoltaic (PV) system, located in a hybrid power grid. Also, this dissertation proposes two new techniques such as a Non-Linear (NL) controller and a Proportional-Integral (PI) controller for mitigating the adverse effects of cyber-attacks on the mentioned devices, and a new detection and mitigation technique based on the voltage threshold for the Supercapacitor Energy System (SES). Simulation results obtained through the MATLAB/Simulink software show the effectiveness of the proposed new control methods for power quality improvement. Also, the proposed methods perform better than conventional methods

Intelligent cascaded adaptive neuro fuzzy interface system controller fed KY converter for hybrid energy based microgrid applications

Purpose. This article proposes a new control strategy for KY (DC-DC voltage step up) converter. The proposed hybrid energy system fed KY converter is utilized along with adaptive neuro fuzzy interface system controller. Renewable energy sources have recently acquired immense significance as a result of rising demand for electricity, rapid fossil fuel exhaustion and the threat of global warming. However, due to their inherent intermittency, these sources offer low system reliability. So, a hybrid energy system that encompasses wind/photovoltaic/battery is implemented in order to obtain a stable and reliable microgrid. Both solar and wind energy is easily accessible with huge untapped potential and together they account for more than 60 % of yearly net new electricity generation capacity additions around the world. Novelty. A KY converter is adopted here for enhancing the output of the photovoltaic system and its operation is controlled with the help of a cascaded an adaptive neuro fuzzy interface system controller. Originality. Increase of the overall system stability and reliability using hybrid energy system fed KY converter is utilized along with adaptive neuro fuzzy interface system controller. Practical value. A proportional integral controller is used in the doubly fed induction generator based wind energy conversion system for controlling the operation of the pulse width modulation rectifier in order to deliver a controlled DC output voltage. A battery energy storage system, which uses a battery converter to be connected to the DC link, stores the excess power generated from the renewable energy sources. Based on the battery’s state of charge, its charging and discharging operation is controlled using a proportional integral controller. The controlled DC link voltage is fed to the three phase voltage source inverter for effective DC to AC voltage conversion. The inverter is connected to the three phase grid via an LC filter for effective harmonics mitigation. A proportional integral controller is used for achieving effective grid voltage synchronization. Results. The proposed model is simulated using MATLAB/Simulink, and from the obtained outcomes, it is noted that the cascaded adaptive neuro fuzzy interface system controller assisted KY converter is capable of maintaining the stable operation of the microgrid with an excellent efficiency of 93 %.Мета. У цій статті пропонується нова стратегія управління перетворювачем KY (підвищення напруги постійного струму). Пропонована гібридна енергетична система, що живиться перетворювачем KY, використовується разом із контролером системи адаптивного нейро-нечіткого інтерфейсу. Відновлювані джерела енергії останнім часом набули величезного значення внаслідок зростання попиту на електроенергію, швидкого виснаження викопного палива та загрози глобального потепління. Однак через властиву їм уривчастість ці джерела забезпечують низьку надійність системи. Таким чином, гібридна енергетична система, що включає енергію вітру/фотоелектричних елементів/акумулятору, реалізована для отримання стабільної і надійної мікромережі. Як сонячна, так і вітрова енергія доступні з величезним невикористаним потенціалом, і разом вони забезпечують понад 60 % щорічного чистого приросту нових потужностей з виробництва електроенергії в усьому світі. Новизна. Перетворювач KY використовується тут для підвищення вихідної потужності фотоелектричної системи, і його робота керується за допомогою каскадного контролера системи з адаптивним нейро-нечітким інтерфейсом. Оригінальність. Підвищення загальної стабільності та надійності системи за допомогою гібридної енергетичної системи, що живиться перетворювачем KY і використовується разом з контролером системи з адаптивним нейро-нечітким інтерфейсом. Практична цінність. Пропорційний інтегральний контролер використовується в системі перетворення енергії вітру на основі асинхронного генератора з подвійним живленням для управління випрямлячою роботою з широтно-імпульсною модуляцією для забезпечення регульованої вихідної напруги постійного струму. Акумуляторна система накопичення енергії, в якій використовується акумуляторний перетворювач для підключення до кола постійного струму, зберігає надмірну потужність, що виробляється з відновлюваних джерел енергії. Залежно від стану заряду акумулятора, процес його зарядки і розрядки контролюється за допомогою пропорційного інтегрального контролера. Керована напруга кола постійного струму подається на трифазний інвертор джерела напруги для ефективного перетворення постійної напруги змінну. Інвертор підключений до трифазної мережі через LC-фільтр для ефективного придушення гармонік. Пропорційний інтегральний регулятор використовується для досягнення ефективної синхронізації напруги мережі. Результати. Запропонована модель змодельована з використанням MATLAB/Simulink, і з отриманих результатів випливає, що каскадний адаптивний нейро-нечіткий інтерфейс із системним контролером та перетворювачем KY здатний підтримувати стабільну роботу мікромережі з чудовим ККД 93 %

Z Source Inverter Topologies-A Survey

Need for alternative energy sources to satisfy the rising demand in energy consumption elicited the research in the area of power converters/inverters. An increasing interest of using Z source inverter/converter in power generation involving renewable energy sources like wind and solar energy for both off grid and grid tied schemes were originated from 2003. This paper surveys the literature of Z source inverters/converter topologies that were developed over the years

Application of Power Electronics Converters in Smart Grids and Renewable Energy Systems

This book focuses on the applications of Power Electronics Converters in smart grids and renewable energy systems. The topics covered include methods to CO2 emission control, schemes for electric vehicle charging, reliable renewable energy forecasting methods, and various power electronics converters. The converters include the quasi neutral point clamped inverter, MPPT algorithms, the bidirectional DC-DC converter, and the push–pull converter with a fuzzy logic controller

Design and Control of Power Converters 2019

In this book, 20 papers focused on different fields of power electronics are gathered. Approximately half of the papers are focused on different control issues and techniques, ranging from the computer-aided design of digital compensators to more specific approaches such as fuzzy or sliding control techniques. The rest of the papers are focused on the design of novel topologies. The fields in which these controls and topologies are applied are varied: MMCs, photovoltaic systems, supercapacitors and traction systems, LEDs, wireless power transfer, etc

Optimal Controller Design and Dynamic Performance Enhancement of High Step-up Non-Isolated DC-DC Converter for Electric Vehicle Charging Applications

Ideally, traditional boost converters can achieve a high conversion ratio with a high-duty cycle. But, in regular practice, due to low conversion efficiency, RR reverse-recovery, and EMI (electromagnetic interference) problems, the high voltage gain cannot be performed, whereas CIBC (coupled inductor-based converters) can achieve high voltage gain by re-adjusting the turn ratios. Even though the leakage inductor of the CI (coupled inductor) makes some problems like voltage spikes on the main connectivity switch, high power dissipation, and voltage pressure can be minimized by voltage clamp. In this paper, a non-isolated DC-DC converter with high voltage gain is demonstrated with 3 diodes, 3 capacitors, 1-inductor, and a coupled inductor. The main inductor is connected to the input to decrease the current ripple. The voltage stress at main switch S is shared by diode D1 and capacitor C1 and the main switch is turned ON under zero current, hence it turns to low switching losses. This paper proposes two controllers like proportional-integral (PI) controller and fuzzy logic (FLC) for dc-dc converter. Furthermore, it demonstrates the operation, design, mathematical analysis, and performance of DC-DC converter using controllers for efficient operation of the system is performed using simulations in MATLAB 2012b